Warming arrangement for a power plant

Abstract

The present disclosure relates generally to power plants and more specifically to warming systems for steam turbine plants that prepare the steam plant for either start-up or stand-by operation.

1 . A warming arrangement, for a power plant, comprising:
 at least a first steam turbine, for expanding steam; and   a first warming system, the first warming system comprising:
 a first makeup line, fluidly connected to the first steam turbine, for directing the first warming gas into the first steam turbine; 
 a first recycle line, fluidly connected to the first steam turbine, for conveying the first warming gas from the first steam turbine, 
 a first gas moving device, in either the first makeup line or the first recycle line upstream of the steam turbine, configured to move the first warming gas through the first warming system; and 
 a first heater, in either the first makeup line or the first recycle line, configured to heat the first warming gas before it enters the first steam turbine; 
 a first pressure measurement device configured and arranged to determine a gauge pressure in the first steam turbine; and 
 a controller, configured to control a flow rate of the first warming gas through the first steam turbine, based on the first pressure measurement device; and and configured to control at least one of a temperature of the first warming gas and the flow rate of the first warming gas based on the moisture content measured by a first moisture measurement device; 
   wherein the first steam turbine has a feed line and an exhaust line which in combination are arranged to direct a main steam through the first steam turbine during operation, wherein points of connection of the first makeup line to the first steam turbine and points of connection of the first recycle line to the first steam turbine are distinct and separate from points of connection of the feed line to the first steam turbine and points of connection of the exhaust line to the first steam turbine; and
 wherein the feed line includes a feed valve wherein the first recycle line is connected to the feed line so as to enable the first warming gas to flow through the feed line into the first steam turbine via the feed line. 
   
     
     
         2 . The arrangement of  claim 1  wherein the controller is configured and arranged to control the flow rate of the first gas moving device. 
     
     
         3 . The arrangement of  claim 1  wherein each of the first makeup line and the first recycle line includes at least one block valve configured to isolate the first warming system from the first steam turbine during operation of the first steam turbine. 
     
     
         4 . The arrangement of  claim 1  wherein the first moisture measurement device is located and arranged to estimate a moisture content of the first warming gas in the first steam turbine. 
     
     
         5 . The arrangement of  claim 4  wherein the moisture measurement device is located in the first steam turbine. 
     
     
         6 . The arrangement of  claim 1  further comprising a heat recuperator configured to transfer thermal energy between the first warming gas flowing through the first makeup line and the first recycle line. 
     
     
         7 . The arrangement of  claim 1  wherein the first gas moving device is located in the first makeup line upstream of the heat recuperator. 
     
     
         8 . The arrangement of  claim 1  wherein the first recycle line is fluidly connected the first makeup line to create a circular first warming gas flow path that includes the first steam turbine, the first gas moving device and the first heater. 
     
     
         9 . The arrangement of  claim 1  wherein the first recycle line is connected to the first makeup line by means of a control valve wherein the control valve includes a first warming gas flow path therethrough from:
 outside the circular flow path to inside and the circular flow path; and from
 the first recycle line to the first makeup line. 
 
 
     
     
         10 . The arrangement of  claim 1  further comprising a second steam turbine and a second warming system for warming the second turbine using a second warming gas. 
     
     
         11 . The arrangement of  claim 10  the second warming system further comprising a third steam turbine for further expanding steam from the second steam turbine; and
 a condenser connected to an outlet of the third steam turbine. 
 
     
     
         12 . The arrangement of  claim 10  wherein each of the steam turbines includes a plurality of makeup lines with an end point fluidly connected to and axially distributed along the steam turbine so as to enable a plurality of warming gas streams to be fed into the steam turbine. 
     
     
         13 . The arrangement of  claim 1  wherein the warming system further includes a temperature measurement device that is connected to the controller and configured to measure a temperature of the steam turbine. 
     
     
         14 . A warming arrangement, for a power plant, comprising:
 at least a first steam turbine, for expanding steam; and   a first warming system, the first warming system comprising:
 a first makeup line, fluidly connected to the first steam turbine, for directing the first warming gas into the first steam turbine; 
 a first recycle line, fluidly connected to the first steam turbine, for conveying the first warming gas from the first steam turbine, 
 a first gas moving device, in either the first makeup line or the first recycle line upstream of the steam turbine, configured to move the first warming gas through the first warming system; and 
 a first heater, in either the first makeup line or the first recycle line, configured to heat the first warming gas before it enters the first steam turbine; 
 a first pressure measurement device configured and arranged to determine a gauge pressure in the first steam turbine; and 
 a controller, configured to control a flow rate of the first warming gas through the first steam turbine, based on the first pressure measurement device; and and configured to control at least one of a temperature of the first warming gas and the flow rate of the first warming gas based on the moisture content measured by a first moisture measurement device; 
   wherein the first steam turbine has a feed line and an exhaust line which in combination are arranged to direct a main steam through the first steam turbine during operation, wherein points of connection of the first makeup line to the first steam turbine and points of connection of the first recycle line to the first steam turbine are distinct and separate from points of connection of the feed line to the first steam turbine and points of connection of the exhaust line to the first steam turbine; and
 wherein the first recycle line is fluidly connected to the feed line so as to enable the first warming gas to flow from the first recycle line into the feed line prior to entering the first steam turbine via the feed line. 
   
     
     
         15 . The arrangement of  claim 14 , wherein the connection between the first recycle line and the feed line comprises a mixing valve configured to control the ratio of first warming gas from the first recycle line to the first warming gas from the feed line provided to the first steam turbine. 
     
     
         16 . The arrangement of  claim 14  wherein the warming system further includes a temperature measurement device that is connected to the controller and configured to measure a temperature of the steam turbine. 
     
     
         17 . The arrangement of  claim 14  wherein the first moisture measurement device is located and arranged to estimate a moisture content of the first warming gas in the first steam turbine. 
     
     
         18 . The arrangement of  claim 14  wherein the controller is configured and arranged to control the flow rate of the first gas moving device.